The present invention is directed to a method and apparatus for manufacturing a recyclable container having a disposable liner. More particularly, the present invention is directed to container having a disposable liner within a reusable shell, which together forms a clean, sanitary, recyclable container which does not need to be sterilized after each use.
Disposable liners for containers have long been used to simplify cleaning of the container and, as is the case with disposable infant formula holders, to allow for withdrawal of formula without requiring introduction of air into the container as in McLeod, U.S. Pat. No. 3,406,853. Disposable liners have also been used for a vacuum bottle for storing hot or cold liquids as described in Frew, et al., U.S. Pat. No. 3,933,263 in order to keep the inside of the vacuum bottle free from residue. A similar disclosure involving reuse of a semi-rigid shell that supports a disposable liner fitted inside the shell is found in Sondel, U.S. Pat. No. 3,739,827.
However, known liner/container systems typically require complex or unwieldy holding devices for joining the liner to the reusable container. In many conventional designs, a liner must be manually inserted into a container, and a threaded lid screwed onto the container to catch and hold the disposable liner. What is needed is an efficient, fully automateable procedure and apparatus for making containers having disposable liners. This procedure must not require complex molding for the container, or unnecessary thread, latch, or catch mechanisms for holding the disposable liner.
It has been suggested to blow mold a double layered container by blow molding a liner within an outer container shell using an injection molded parison or preform to form the liner. In Makowski, U.S. Pat. No. 3,091,000 and Aoki, U.S. Pat. No. 3,943,219, a parison for a liner is molded around a core pin in an injection mold. The core pin is then employed to insert the parison into a container shell and an inflating fluid is introduced through the core pin to blow mold the parison into a liner within the outer container shell. Neither the Makowski container shell nor the Aoki container shell is disclosed to be reusable and neither liner is disclosed to be removable. Additionally, the liners disclosed in Makowski and Aoki fail to provide a means for a sanitary seal between the liner and a closure for the container thus requiring that the container shell be made sanitary prior to use with foods or beverages.